title: Long term trends of Hg uptake in resident fish from a polluted estuary.
abstract: Mercury contamination of fish is dependent upon a system's ability to transform inorganic Hg into biologically available forms; however, fish biometrics also play an important role. To assess long term trends in Hg concentrations in sand flathead (Platycephalus bassensis) a polynomial model, corrected for fish length, was used to evaluate temporal trends and spatial variability, while growth rates were estimated using the Von Bertalanffy length-at-age model. Hg concentrations showed no decrease over time, and generally remained near recommended consumption levels (0.5 mg kg(-1)). Previously reported spatial differences in Hg concentrations were not supported by the data once the models were corrected for fish length. Growth rate variation accounted for a large part of the previously published spatial differences. These results suggest that inclusion of fish biometrics is necessary to facilitate an accurate interpretation of spatial and temporal trends of contaminant concentrations in long term estuarine and marine monitoring programs.
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001, Australia. hugh.jones@utas.edu.au
authors.forename: Hugh J
authors.initials: HJ
authors.lastname: Jones
authors.forename: Kerrie M
authors.initials: KM
authors.lastname: Swadling
authors.forename: Sean R
authors.initials: SR
authors.lastname: Tracey
authors.forename: Catriona K
authors.initials: CK
authors.lastname: Macleod
mesh_terms: D000818:Animals; D004784:Environmental Monitoring; D063366:Estuaries; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D008628:Mercury / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Biometric modelling; Estuarine management; Long term monitoring; Mercury bioaccumulation; Von Bertalanffy growth curves